钢与钢筋混凝土混合结构的等效阻尼比分析研究

发布时间：2018-06-21 14:32

本文选题：混合结构 + 等效阻尼比　；参考：《兰州理工大学》2013年硕士论文

【摘要】：随着工业技术的发展,建筑结构的形式已越来越多元化,混合结构已成为土木工程师经常遇到的结构类型。混合结构整体阻尼的确定显得尤为重要,它将直接影响结构抗震分析结果的可靠性。对于单一材料结构的阻尼比规范中有着明确的规定,但是对于混合结构,由于阻尼机理的复杂性,其等效阻尼比目前还没有给出统一的科学的取值。该文针对剪切型加层混合结构、一般多高层以及超高层混合结构的阻尼比进行了探讨和分析,具体研究分析内容如下： (1)阐述混合结构的发展及应用前景,指出目前混合结构等效阻尼比的取值存在的问题,并介绍现阶段国内外在混合结构等效阻尼比研究方面的科研现状和研究成果。 (2)探讨现有的各种结构阻尼理论的发展概况、适用范围及优缺点,分析阻尼的实质、常用的计算假定以及给出阻尼参数具体的表达方法。 (3)介绍模态参数识别的概念以及参数识别的理论背景,研究分析数字信号分析系统的一般原理和参数识别的主要过程。 (4)对于剪切型加层混合结构,从复阻尼假定出发,通过能量守恒原理推导出了其在双向振动下的等效阻尼比的简化公式；同时用SAP2000有限元软件建立一个钢与钢筋混凝土混合结构的模型进行分析,并用该简化公式计算等效阻尼比,然后通过设置两种验证方案进行对比分析,结果证明该简化公式是可适用的。 (5)对于一般多高层结构,应用ANSYS有限元软件模拟振动台模型试验,通过输入白噪声并求出测点的响应信号,然后基于模态参数识别原理在频域内用MATLAB语言分别按照有理分式多项式法和正交多项式法编程求解结构的阻尼比。通过仿真分析对比结果表明了该方法及MATLAB程序的有效性和可行性。最后得出,借助于ANSYS有限元软件具有的材料阻尼单元建模功能,运用以上方法能够为多高层混合结构的等效阻尼比的求解提供了一种新的思路和计算方式。 (6)针对超高层混合结构,应用Etabs有限元软件对其进行动力分析,在构建阻尼矩阵时,通过采取各种阻尼比值作为不同的计算工况,对比分析出阻尼特性对超高层混合结构的动力响应影响,结果表明对同一超高层混合结构,即使阻尼比相差约1%时,也会引起结构体系振动响应相对误差20%左右的变化,相差约2%时,更是达到了40%的变化。
[Abstract]:With the development of industrial technology, the form of building structure has become more and more diversified, and hybrid structure has become a common structural type encountered by civil engineers. It is very important to determine the damping of hybrid structures, which will directly affect the reliability of seismic analysis results. The damping ratio of a single material structure is clearly defined in the code, but for a hybrid structure, due to the complexity of the damping mechanism, the equivalent damping ratio has not yet given a unified scientific value. In this paper, the damping ratio of shear-type hybrid structure, multi-tall and super-tall hybrid structures is discussed and analyzed. The main contents are as follows: 1) the development and application prospects of hybrid structures are described. It is pointed out that there are some problems in the selection of equivalent damping ratio of hybrid structures at present. This paper also introduces the present situation and achievements of the research on the equivalent damping ratio of hybrid structures at home and abroad. (2) the development situation, application scope, advantages and disadvantages of the existing structural damping theories are discussed, and the essence of damping is analyzed. This paper introduces the concept of modal parameter identification and the theoretical background of parameter identification. The general principle of digital signal analysis system and the main process of parameter identification are studied. Based on the energy conservation principle, the simplified formula of equivalent damping ratio under bidirectional vibration is derived, and a model of steel-reinforced concrete mixed structure is established by using SAP2000 finite element software. The simplified formula is used to calculate the equivalent damping ratio, and then the two verification schemes are compared and analyzed. The results show that the simplified formula is applicable to the general multi-tall structures. The finite element software ANSYS is used to simulate the shaking table model test, and the response signal of the measuring point is obtained by inputting the white noise. Then the damping ratio of the structure is calculated by the rational fraction polynomial method and the orthogonal polynomial method in the frequency domain based on the modal parameter identification principle. The simulation results show that the method and MATLAB program are effective and feasible. Finally, with the help of ANSYS finite element software, the modeling function of material damping element is obtained. The above method can provide a new way of thinking and calculation for solving the equivalent damping ratio of multi-high-rise hybrid structures. (6) for super-tall hybrid structures, the Etabs finite element software is used to carry out the dynamic analysis. In the construction of damping matrix, by taking various damping ratios as different calculation conditions, the effects of damping characteristics on the dynamic response of super-tall hybrid structures are compared and analyzed. The results show that for the same super-tall hybrid structures, Even when the damping ratio is about 1, the relative error of vibration response of the structural system will change by about 20%, and when the difference is about 2, the variation will reach 40%.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU311.3

【参考文献】